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Human salmonella isolates 2011

01 January 2011

Enteric reference testing

Please note: As of 1 July 2025, the New Zealand Institute for Public Health and Forensic Science (PHF Science) is the new name for the Institute of Environmental Science and Research (ESR). Research and reports published prior to this date may reference the organisation’s former name.

Click to download the isolates data below, or scroll to read the annual summary

Annual summary 2011

There were 1095 human Salmonella isolates confirmed in 2011 (2010 n= 1195). S. Typhimurium phage type RDNC-May 06 was the predominant serotype, representing 7% of total isolates (7% 2010). Several Salmonella serotypes showed an increase this year in comparison with 2010 with the most significant increase observed in S. Enteritidis (9.5% in 2010 to 12% in 2011) and S. Typhi (2.5% in 2010 to 4% in 2011). The most significant decrease was seen in S. Typhimurium overall (from 50% in 2010 to 45% in 2011).

Significant Outbreaks and/or Clusters:
S. Agona: An increase of S. Agona was detected in the Auckland region during the month of March. All cases had attended the same social function.

S. Typhimurium phage type RDNC-May 06:
In May 2006, a new S. Typhimurium RDNC (reacts with phages but does not conform to a known phage pattern) phage type pattern was confirmed in New Zealand. The pattern was designated RDNC-May 06. The first isolate was from a 3-year-old male from Auckland with no history of overseas travel. For the next 2 years, S. Typhimurium phage type RDNC-May 06 spread throughout the North Island. In June 2008, the first human case was confirmed in the South Island (a 2-year-old male from Canterbury). Since 2006, human and non-human isolates of this new phage pattern have increased in prevalence, while other phage patterns have decreased. S. Typhimurium phage type RDNC-May 06 has spread from a single location to the entire country. It peaked at 85 human cases in 2010. Seventy-three human and 42 non-human isolates were confirmed in 2011. It has established itself as a pathogen in animals, particularly cats, cattle and horses, but has not yet been confirmed in sheep. In humans, DT RDNC-May 06 is isolated most of the year, with a peak in spring.